<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        div{
            width: 600px;
            height: 400px;
            background-color: pink;
            display: flex;
            /*flex-direction: column;
            flex-wrap: wrap;*/
            flex-flow:column wrap;
        }
        div span{
            width: 150px;
            height: 100px;
            background-color: skyblue;
        }
    </style>
</head>
<body>
<div>
    <span>1</span>
    <span>2</span>
    <span>3</span>
    <span>4</span>
    <span>5</span>
    <span>6</span>
</div>
</body>
</html>
